I’m Josie, the Remodeling Designer and Office Manager here at AP. At 21, I’ve grown up around construction and design, and now I have the privilege of leading our creative process and connecting with clients to bring their dream spaces to life. I also create 3D renderings for our client projects to help them visualize the finished design before we even begin. On top of that, I manage our marketing and social presence—so if you’ve seen our work online, I probably had a hand in sharing it!
My roots run deep in Jacksonville, but my story is also shaped by my family’s journey. My parents immigrated from Albania and now work alongside me every day. Together, we’ve built more than just beautiful homes—we’ve built a company grounded in hard work, integrity, and a genuine love for what we do.
Homeowners often explore accessory dwelling units to create rental income, support multigenerational living, or increase property value. ADUs offer flexible design choices and various construction methods, so overall pricing varies significantly. Many people struggle to understand which factors drive expenses because each type of structure requires different materials, permitting steps, and site preparation. A detailed guide helps clarify what influences an additional dwelling unit and how to compare options effectively.
As homeowners, they benefit from understanding how size, layout, and location shape their budget. The additional dwelling unit cost also depends on zoning requirements, utility connections, foundation work, and interior finishes. Careful planning prevents surprises later in the project. Whether the goal involves maximizing rental potential or creating a private space for family members, accurate cost projections help ensure the ADU fits both lifestyle needs and financial goals.
Detached ADUs Require Full Structural Builds
Detached units sit separate from the main home, often in the backyard or on another section of the lot. They function like small standalone houses, so they require full foundations, framing, roofing, insulation, plumbing, and electrical systems. These units usually carry the highest overall cost because the builder must create an independent structure from the ground up.
A detached ADU often costs more than other ADU types due to additional site work. Soil grading, tree removal, utility trenching, and new driveways can sometimes add significant costs. The choice of finishes also influences the final total. High-efficiency windows, premium siding, and specialized roofing materials increase longevity but raise construction costs.
A 500 sq ft detached ADU usually costs between $150,000 and $220,000 in Jacksonville, which fits modest budgets and works well for efficient studio living. A 600 sq ft detached ADU typically costs $165,000 to $240,000, and this size provides enough room for a private bedroom, bathroom, and a functional kitchen. A larger 800 sq ft detached ADU often costs $200,000 to $300,000, and this footprint may include a full bedroom, a larger kitchen, and generous storage space. Some homeowners pursue a 1200 sq ft detached ADU costing between $310,000 and $420,000 when they want a two-bedroom layout with full living areas. These larger footprints often match small family homes and command higher rental rates.
Attached ADUs Integrate With Existing Structures
Attached accessory units share at least one wall with the primary residence. This option reduces some structural costs by using the existing foundation and framework for the new unit. Builders still need to create private entrances, separate utilities in many cases, and upgrade fire separation materials. These requirements influence the attached ADU cost, but the total often stays lower than that of a detached structure.
Attached units often require special attention to the transition between the main home and the new living space. Soundproofing, HVAC integration, and roofline alignment all influence the budget. The project may also trigger code requirements for upgrades in the main home, such as electrical panel improvements or structural reinforcements.
A 500 sq ft attached ADU usually costs $120,000 to $165,000 in Jacksonville, making this footprint an affordable option for compact studio living. A 600 sq ft attached ADU costs often fall between $135,000 and $180,000, and this size provides enough room for a bedroom, bathroom, and an efficient kitchen. Larger attached layouts, such as 800 sq ft, typically cost $160,000 to $230,000, and this extra space supports a full bedroom, a bigger kitchen, and improved storage. Some homeowners choose a 1200 sq ft attached ADU costing between $245,000 and $350,000 when they want a comfortable two-bedroom layout connected to the main home. These larger attached units blend seamlessly with the existing structure and create substantial long-term value.
Garage Conversion ADUs Provide a Budget-Friendly Alternative
Garage conversions are among the most affordable ADU paths. A builder transforms an existing structure into a livable space. The foundation, walls, and roof already exist, so material costs decrease considerably. Yet the contractor must bring the space up to residential standards, so insulation, plumbing lines, electrical rewiring, and new flooring often create substantial expenses.
The ADU garage conversion cost depends on the quality of the current garage. Old or deteriorated structures require significant repair before conversion work begins. Ceiling height, structural integrity, and moisture issues all influence the overall cost. A basic garage conversion often fits smaller budgets, but premium conversions approach the price of new construction.
Garage conversions work well for efficient studios because the structure already exists. A basic garage conversion ADU in Jacksonville usually costs between $90,000 and $140,000, and this level of renovation supports a compact layout with essential living space. Some homeowners expand the design to include multiple bedrooms. A 2-bedroom inside a garage conversion typically costs $150,000 to $200,000, since interior partitions, additional plumbing lines, upgraded HVAC systems, and larger electrical loads increase labor and material costs. Families who want more living space often consider adding a second story above the garage, though. However, take the project into a higher tier, with totals ranging from $210,000 to $300,000 depending on structural reinforcement needs and finish selections.
Site Conditions Influence Labor and Material Requirements
Every property presents unique challenges. Sloped lots require substantial grading, retaining walls, and drainage improvements. These corrections often add $4,000 to $15,000, depending on the volume of soil moved. Rocky soil increases excavation labor and may raise costs by $2,000 to $6,000. Limited access may require contractors to carry materials by hand rather than by truck, increasing labor hours.
Jacksonville’s sandy soil frequently needs compaction, and this preparation usually adds $3,000 to $8,000 before foundation work even begins. Tree removal also affects total pricing, with costs typically ranging from $500 to $2,500 per tree, depending on size and location. These factors contribute to overall ADU construction costs and often surprise homeowners who did not plan for site preparation.
Utility access also shapes costs. Long distances between the main home and the ADU require additional trenching for water, sewer, and electrical connections, which often adds $2,500 to $12,000. Some older neighborhoods require panel upgrades, and electrical replacements typically cost $2,000 to $5,000. Homes outside city sewer areas may need septic system expansion, which can cost $4,000 to $12,000.
Modern ADUs frequently include energy-efficient appliances and updated code requirements, which influence load calculations and panel upgrades. These utility adjustments play a significant role in ADU budgets and help explain why cost estimates vary widely from property to property.
Interior Finishes and Layout Choices Influence Long-Term Value
Interior selections often have the most significant impact on the final budget. Entry-level finishes help control spending, with vinyl plank flooring at $3 to $5 per square foot, stock cabinets at $3,000 to $6,000, and basic bathroom packages at $2,500 to $5,000. Jacksonville homeowners who want mid-range finishes usually spend more, especially when tile showers cost $4,000 to $9,000, quartz countertops cost $3,500 to $7,000, and upgraded doors or trim packages add $3,000 to $8,000. Premium finishes often increase total project costs by $30,000 to $80,000, depending on the ADU’s size.
Layout choices also matter. A 2-bedroom ADU requires additional framing, closets, HVAC distribution, and egress windows, which add more labor and materials. These layout changes usually add $20,000 to $45,000 to the cost of a single-bedroom ADU of the same size. Compact open floor plans reduce framing costs and maximize efficiency, while traditional layouts create more privacy but require more interior materials.
Budget Planning Tips for Accurate and Predictable ADU Projects
Homeowners should create a detailed budget that includes design, engineering, permitting, site work, materials, finishes, and contingency funds. Architectural plans typically cost $4,000 to $9,000, engineering reports cost $1,500 to $4,000, and Jacksonville permitting fees often range from $3,000 to $8,000, depending on the size of the ADU.
Builders often recommend a contingency of ten to twenty percent to cover unexpected issues such as drainage corrections, structural adjustments, or electrical upgrades. Precise planning prevents cost overruns and ensures the ADU meets long-term goals.
Designing Your ADU with Long-Term Vision at AP Advanced
We plan every ADU with long-term function in mind. Our team helps homeowners select layouts, finishes, and storage solutions that support comfort, durability, and cohesive design. When we guide clients through kitchen upgrades, cabinetry choices, efficient layouts, or interior finish options, we keep the entire home remodel organized and aligned with their goals.
We often pair ADU work with additional home improvement projects to create a seamless result. Many homeowners choose bathroom updates, kitchen refreshes, or targeted renovation upgrades while we complete the ADU. Others improve outdoor areas with patios, garages, or outdoor kitchen plans that complement the new unit. Through structured design planning and coordinated construction, we help homeowners build an ADU that adds lasting value and aligns with their long-term vision.
Key Insights for Homeowners Planning an ADU Investment
Understanding the many factors that shape an ADU budget helps homeowners create realistic expectations. Each type of structure has unique costs, so homeowners should carefully compare detached, attached, and conversion options. Square footage, interior finishes, and site conditions significantly influence the final price. Homeowners should also ensure that all planning, budgeting, and design decisions comply with local ADU laws, including zoning requirements, setback rules, utility regulations, and permitting processes, as these can affect both feasibility and total project cost.